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1. Field of Invention
This invention relates to processes for splicing the cut ends of a continuous strip of packets used to hold granular bulk material. More particularly, the invention relates to processes for splicing the cut ends of a continuous strip of packets utilizing heat or ultrasonic energy and splicing devices used for those processes.
2. Description of Related Art
Continuous strips of material or webs are manufactured for many uses. One such use is for the manufacture of continuous strips of packets or bags containing bulk materials such as desiccants or deodorizers. For example, a continuous strip of packets of a deoxidizing agent are disclosed in U.S. Pat. No. 4,752,002. In use, one or more of the individual packets of this product are severed from the continuous strip and placed with or in a container to deoxidize the air associated therewith or contained therein.
Another continuous strip of packets containing bulk material is disclosed in U.S. Pat. No. 4,957,521, wherein the packets are formed from a heat fusible material. The strip of packets contains perforations between each individual packet which perforations can be used to trigger an automatic cutting machine to sever the packet from the strip. The packets of this strip preferably contain a desiccant material.
U.S. Pat. No. 3,189,227 discloses a continuous strip of packets, each of which contain a single dosage of a drug or ointment. Other continuous strips of packets of products are disclosed in, for example, U.S. Pat. Nos. 3,751,875, 3,254,828, 4,467,207, 4,680,205, 4,844,956, 4,907,393, 5,157,902 and 5,887,722.
The types of products that are conventionally loaded into these packets or bags include desiccants, odor absorbers, oxygen absorbers and the like. Many of these packets or bags are formed from packaging materials which allow air to flow through the packaging material to permit the desiccant or absorber contained therein to remove certain material(s) from the air, such as water, oxygen or odors.
Form-fill-and-seal machines are commonly used to produce these continuous strips of packets. Conventionally, these machines form a packet by a process of sealing the continuous length of material to itself, filling packets formed by that sealing process with a bulk material and finally, sealing the remaining open end of the packets. Different technologies can be used to form the seals on these packets, depending on the type and composition of the packaging material and the method of formation of the packets. Pressure, heat or some form of sealing energy is applied to the packaging material, such as by means of heated seal bars, impulse sealers or ultrasonic heater to create the seals. Usually these packets have three seal areas where the packaging material that is used to produce the packets is sealed to itself: two end seals and one edge seal on the back of the packet. After formation and filling with the bulk material, the packets are generally used either as single packets or in the form of a continuous strip that is wound onto a reel or fan-folded into a box for storage and shipping.
During the manufacture of these packets, there are frequently situations when the form-fill-and-seal machine must be stopped during a production run due to mechanical or electrical problems, scheduled maintenance or adjustments to the packets. In addition, for quality control and for other reasons, the packets from the continuous strip must often be sampled.
In order to insure that the specified minimum number of packets are present on the continuous strip, on a reel or in a packaging box for the packets, there are often situations when two ends of the continuous strip must be spliced together. Further, if a sample must be removed from the continuous strip, the loose ends of the continuous strip which are produced by the sampling process must be spliced together to reform the continuous strip. In addition, if a problem occurs during processing of the continuous strip which results in damage to one or more packets, it is necessary to cut out the damaged packet(s) from the continuous strip necessitating the splicing of the two remaining ends of the continuous strip.
The traditional preferred method to splice two ends of a continuous strip of packets together is to use a section of adhesive tape to connect the two loose ends. In fact, some consumers of these packets require use of a colored piece of adhesive tape to splice the loose ends of a continuous strip together to indicate where the splice exists in the continuous strip.
The use of tape to seal continuous strips of material is disclosed, for example, in U.S. Pat. Nos. 4,859,270 and 6,076,671. A process for splicing a continuous web of paper using an adhesive tape is disclosed in U.S. Pat. No. 6,228,205. Splicing continuous webs of material with an adhesive is also disclosed in U.S. Pat. Nos. 6,264,130 and 5,253,819. Other splicing processes are disclosed in U.S. Pat. Nos. 5,468,321 and 6,086,806.
The process of splicing the ends of other compositions of material is also well known. However, the splicing of these materials is not relevant to the splicing of a continuous packaging material for a number of reasons, including the significant differences in the composition of the materials used to form the continuous strip. As an example of the splicing of these dissimilar products, photographic film is often spliced, as disclosed in U.S. Pat. No. 3,556,912 and 5,064,488. The splicing of a soft paper web material is disclosed in U.S. Pat. No. 5,360,502 and the splicing of endless rubber belts is disclosed in U.S. Pat. Nos. 2,182,169, 2,500,273 and 2,702,070. An apparatus for preparing and positioning a continuous roll of material which contains a recurring pattern for splicing is disclosed in U.S. Pat. No. 5,284,197. However, this patent does not disclose the method of splicing the two ends of the material together.
As stated above, the conventional preferred method for splicing loose ends of a continuous strip of packets containing bulk material, such as desiccants, is by using an adhesive tape. These packets, especially desiccant packets, are widely used in the pharmaceutical, nutritional and diagnostic industry. The packets are packaged with the finished goods to provide moisture control and avoid moisture induced degradation of the packaged products.
Modern packaging facilities for pharmaceutical, nutritional and diagnostic products run at high speed and require a reliable and fast method of insertion of these individual packets into the packaging for these products, which packaging may be in the form of a bottle, vial or box. The most common method to dispense these packets into the packaging is by use of a machine that cuts the continuous strip of desiccant packets and dispenses the cut individual packets into the packaging. To assure a reliable cutting and dispensing process, the dispensing machine needs a method to sense where the individual packets of the continuous strip begin and end. Some methods for sensing can, for example, measure the length of the packets or the thickness of the packets. (The portion of the packets containing the bulk material is thicker than the seal area separating the packets.) These methods of sensing have disadvantages because the sensor can be confused by the variability of the packet length or fill volume. This confusion can result in a packet being cut in the portion of the packet containing the fill material instead of at the seal area between two individual packets. This type of cutting error results in down time for the packaging line, spill of the bulk material and potential contamination of the product being packaged.
The most advanced method to solve this sensing problem utilizes a continuous strip of bulk material containing punch holes in the seal area between the individual packets as shown, for example, in U.S. Pat. No. 4,957,521 and Japanese Patent No. 9,099,974. This punch hole is then sensed by a light sensor at the dispensing unit. The sensor senses where the seal area between the packets is located and cuts the packet at that location. The light sensor senses this location by sensing differences in light transmission through the packets and through the holes between the individual packets. This difference is so large that this light sensor generally only needs minimal adjustment during processing and is very reliable.
Notwithstanding the advances in the processes for accurately cutting individual packets of bulk material, it is almost unavoidable that continuous strips will contain splices between some of the individual packets. As stated above, the conventional preferred method for splicing the ends of a continuous strip that is accepted in the industry is by taping the cut ends using a colored piece of tape. However, the presence of even a few such taped splices can be detrimental. In fact, oftentimes the consumer of these continuous strips demands that the continuous strip contain no more than a small number of such taped splices. If too many taped splices are present, the entire continuous strip may be rejected. Further, there are often significant problems when adhesive tape is used to form these splices. For example, conventional adhesive tape is not as strong as the original uncut packaging material used in the continuous strip. The use of adhesive tape also requires stopping the packet dispensing machines to remove the spliced tape. Further, the tape material does not have the same physical characteristics as the material that forms the packet, such as permeability. In addition, a taped packet is not as visually appealing to a consumer as a non-taped packet. Finally, the adhesive tape sometimes jams the dispensing machine and does not have as long a life expectancy as that of an untaped seal.
Accordingly, it is an object of this invention to develop a method for splicing continuous strips of packaging material which solves these problems.
It is also an object of the invention to provide a method to splice the cut ends of a continuous strip of packets or bags which hold bulk material.
It is a further object of the invention to disclose a process for splicing the cut ends of a continuous strip of packets or bags holding bulk material, which does not utilize tape to seal the cut ends.
It is a still further object of the invention to disclose a process for splicing the cut ends of a continuous strip of packets or bags used to hold bulk materials which utilizes ultrasonic welding as the splicing method.
It is a still further object of the invention to disclose a process for splicing the cut ends of a continuous strip of packets or bags used to hold bulk material, whereby the two ends are heated and melted or partially melted together.
It is a still further object of the invention to disclose a process for the splicing of the cut ends of a continuous strip of packets or bags used to hold bulk materials, wherein the two cut ends are joined by use of an adhesive material.
These and further objects of the invention are obtained by the processes for production and products used with these processes of the invention disclosed herein.
The present invention is a process for splicing cut ends of a continuous strip of packets or bags used to hold bulk material comprising
forming a continuous strip of packets from packaging material and filling the packets with the bulk material, sealing the ends of the packaging material to form individual packets of the continuous strip, wherein the individual packets share a common sealed area of packaging material, forming an opening in the common sealed area between adjacent packets, cutting the continuous strip entirely across the sealed area of the packets at two separate locations on the continuous strip, wherein each of two remaining cut ends of the continuous strip comprise a sealed section with an opening in that sealed section, and, without using tape, splicing together the two sealed sections of the continuous strip such that the openings in the cut ends of the sealed sections overlap leaving a single opening in the spliced section of the continuous strip.
In one preferred embodiment the two sealed sections are spliced together by use of ultrasonic welding.
In another preferred embodiment the two sealed sections are spliced by heating to melt or partially melt the sealed sections of the continuous strip together.
In a further preferred embodiment, the two sealed sections are spliced together by use of an adhesive.
The invention further encompasses an impulse splicing device useful for splicing a pair of ends of a continuous strip of packets used to hold bulk materials wherein each of the ends of the continuous strip includes an opening in a sealed section, wherein the device comprises a pair of connected arms, each containing a base, wherein one of the bases on one of the arms comprises a lower surface element, a pin secured to the lower surface element and guiding sides secured to the lower surface area, wherein the second base comprises an upper surface element with an opening therein, which upper surface area is secured to the second arm, and wherein the device further comprises an energy supply mechanism connected to the pair of arms to supply energy for melting or partially melting the ends of the continuous strip of packets when the ends are placed between the two bases, the two bases are pressed together and the energy supplying mechanism supplies energy to the bases.
In a further preferred embodiment the invention further comprises an ultrasonic welding tool useful for the splicing of a pair of ends of a continuous strip of packets used to hold bulk materials wherein each of the ends of the continuous strip includes an opening in a sealed section, wherein the device comprises an anvil element comprising a base to which is secured a pin and guiding sides and an ultrasonic energy generator element comprising a hand piece, a horn secured to an end of the hand piece, wherein the horn comprises a resonator element and an opening at one end of the horn, and a power supply to supply energy to the horn.
The invention further comprises a spliced continuous strip of packets or bags used to hold bulk material formed by the processes described above.